Through the point of installing insulation in his 3,600-square-foot custom home near Columbia, S.C., architect Mark Bostic has yet to make or pay for a trip to the local landfill. In Ft. Wayne, Ind., Jeff Zolnik serves about three-quarters of the area's builders with his construction waste recycling business, adding an average of one new customer a day. Meanwhile, Santa Fe, N.M., builder Kim Shanahan sends the foam packaging material he collects on his jobsites to a nearby maker of insulated concrete forms, which Shanahan uses for the stem walls on his latest project.
These are not isolated incidents, but rather indicators of a mainstream movement to reduce and recycle construction and demolition (C&D) waste from residential and light commercial jobsites. From the decades-old concept of optimum value engineering ("OVE," now referred to as "advanced framing") to a maturing infrastructure of C&D waste processing and recycled-content building materials, the suggestion that finding new uses for leftover lumber, drywall, concrete, metal, asphalt shingles, and cardboard is less costly than sending it all to the dump is quickly becoming widespread reality.
The direct-cost benefits of recycling over landfilling C&D waste are proven, especially in markets where processors can handle various C&D materials. But savvy builders also extend the financial formula to their design, estimating, bidding processes, labor deals, and supply chain relationships to realize the savings of buying less and using more of each stick or panel to reduce upfront costs and the expense of managing their waste streams.
The eco-benefits of waste reduction and reuse are equally attractive against any financial gain.
A dedicated C&D waste management plan also earns builders points or credits within almost every green building program. "If the focus of a builder is green [in the context of a program or checklist], then this is a no-brainer," says John Peavey, applied technology director at the NAHB Research Center in Upper Marlboro, Md. "Even if a waste management plan isn't prescribed, it's still easy to implement and delivers tangible benefits."
To fully realize those benefits, however, requires a comprehensive approach of reducing the amount of materials needed to build (without sacrificing quality or code compliance, of course) and recycling, salvaging, or reusing what remains after a phase or project is completed. The commitment also requires a jobsite culture that encourages the efficient use of materials and recycling, as well as an investment of time, effort, and money to enable and codify those habits.
The best way to manage C&D waste is to not create it. About 40 percent of the raw materials consumed in the United States are used in construction, and residential building, renovation, and demolition account for about 58 million tons of C&D trash per year, representing 11 percent of the overall waste stream.
A key consideration for effectively reducing C&D waste is knowing the types of materials that make up the bulk of that waste and then finding ways to use them more efficiently, or not at all. By weight and volume, wood, drywall, and cardboard (from packaging) make up 60 percent to 80 percent of jobsite waste, according to a nationwide study by the California Integrated Waste Management Board.
The products and practices for reducing wood use and waste are established in residential construction and usually rewarded in green building programs. OVE or advanced framing techniques, including three-stud corners and wider on-center floor framing, can reduce the amount of structural lumber required by 25 percent, while engineered lumber products (ELPs) such as I-joists not only enable longer spans and wider spacing to save materials, but also rely on faster-growing and smaller timber species. Factory-built trusses and wall panels also are engineered to optimize lumber and, like ELPs, are less likely to be mis-cut on site, thus reducing the volume of unusable lengths that become waste.
The efficient use of drywall and wood sheathing panels relies mostly on the home's design. Adhering to 2-foot modular dimensions—another OVE tenet—and then supervising crews to take advantage of that layout when they cut and apply the panels will render a smaller waste pile. Similarly, a more detailed set of plans and specifications mitigates on-site confusion and thus mistakes and misapplications among all products.
Smaller houses and fewer floor plans also reduce C&D waste. Shanahan's Vistas Bonitas features two models of 1,100 square feet among only four plans for a 120-unit project. "The size and repetition of floor plans reduces the amount of materials we use," he says. Peavey also notes that building codes can be amended to further mitigate waste by allowing "systems" instead of an assembly of disparate parts.
Reducing the amount of cardboard generated on a jobsite is a tougher nut, as it is used for packaging other products, not building the house. Still, contractors can reduce that waste stream by asking vendors to deliver materials and finish products in returnable containers or select materials that are delivered with minimal or no packaging.
The net effect of these techniques, among others, goes beyond a smaller waste stream and punches a hole in traditional takeoff practices. "Once builders see what's truly left over [after they apply these methods], they really tighten up their bidding processes," says Zolnik, thus reducing or eliminating the waste-factor costs built into most estimates. Some bid docs also might require a recycling plan from a prospective sub or supplier.
Reuse and Recycle
Rare is the jobsite that produces no waste, but a maturing industry for separating, collecting, hauling, and processing recyclable C&D leftovers provides a step prior to the landfill.
Depending on the sophistication of the local recycling industry, builders engaged in a jobsite recycling effort are usually best served by separating materials rather than commingling what can be processed and reused. "Source separation is more complex, but it's also more economically advantageous," writes Mark Lemmon in Recycling Construction and Demolition Wastes. "The materials are ready to go to market [to be recycled] and generally are of higher quality, so they're worth more," perhaps to the point of actually generating revenue from recyclers rather than paying them to take it.
The key to source recycling, says Lemmon, is to match containers—in size and number—to each phase of work to avoid confusion and clutter and keep recycling simple for crews and subs.
It's also smart to match recycling efforts to materials most likely to generate waste and those that aren't found in large volume but are in high demand, such as brick and metals. To collect packaging foam, Shanahan uses reusable plastic bags he gets from his ICF supplier.
In less-mature or remote markets, C&D processing may occur on site. Small-scale, trailer-set grinders for wood, drywall, and cardboard are a larger investment in a jobsite recycling effort, but might pay for themselves by eliminating hauling and dump fees while improving the condition of the site.
Bostic, for instance, used a small wood chipper to turn clearing debris and dimensional lumber waste into landscape mulch and erosion control material for his own custom house.
He relies on local processors and his subs to manage other recyclable waste, including metal roofing, cardboard, concrete (which he buys back crushed to use as permeable roadbed material at less cost than gravel), and drywall. "Right now, the drywall is about a break-even deal," he says of recycling versus landfilling that material, "but once it gets competitive and people start using it for soil amendment and other uses, they might pay me to come and get it."
The local infrastructure for recycling often dictates the extent a builder and his trade partners can go in their efforts. In Indiana, Zolnik purchased containers and processing equipment to facilitate his business in lieu of a mature industry to support it. Peavey, meanwhile, speculates that the rising number and popularity of green building programs—in which waste reduction, recycling, and the use of recycled-content materials can significantly boost a builder's rating—will eventually help the industry to evolve.
Until other entrepreneurs or municipalities follow those examples, however, builders and contractors can focus on indoctrinating crews and subs for when more opportunities are available. "We've created a jobsite culture that makes everyone responsible for collecting and recycling what we can," says Shanahan. "Someday, the market will step up andhelp us." -- BUILDING PRODUCTS
Real-world studies prove the benefits of C&D waste management and jobsite recycling.
For a comprehensive report on C&D waste management and recycling, Joseph Laquatra and Mark Pierce of Cornell University enlisted a custom builder to track and compare his annual waste management practices and related costs. Focusing on the builder's primary waste stream of wood, cardboard, and drywall, alternative methods including source separation recycling and the purchase of a small-scale dump trailer reduced his per-house cost for waste disposal by 46 percent and his annual burden from $9,260 to $5,000.
In Houston, a similar case study using source separation and on-site grinding of wood and drywall waste for site and soil improvement cut the number of hauls to the landfill from nine to three and the total waste generated from 266 cubic yards weighing 85,000 pounds to 90 cubic yards and 13,000 pounds, significantly reducing dump fees.
Throughout New England, hauling and landfill costs for C&D waste routinely top $140 per ton. A Boston-area case study in Recycling Construction and Demolition Wastes calculated source-separated jobsite recycling practices, showing appreciable savings; recycling metals, in fact, turned a profit. "In the worst case, the cost to recycle is not much more than half the cost of disposal," wrote Mark Lemmon, the report's author. "Across almost any construction project, the savings often amount to tens of thousands of dollars," not to mention positive environmental benefits.
- California Integrated Waste Management Board: www.ciwmb.ca.gov
- Construction Materials Recycling Association: www.cdrecycling.org
- Deconstruction Institute: www.deconstructioninstitute.com
- EPA Resource Conservation Challenge: www.epa.gov/epaoswer/osw/ conserve/2007news/08-decon.htm
- NAHB Research Center Toolbase Services: www.toolbase.org/ToolbaseResources/ level3.aspx?BucketID=5&CategoryID=26
- Office of Sustainable Development-Solid Waste & Recycling, City of Portland, Ore.: www.portlandonline.com/osd/index.cfm?c=41683
- Peaks to Prairies' online waste calculator: peakstoprairies.org/p2bande/ Construction/C&DWaste/calculate.cfm
- Recycling Construction and Demolition Wastes: A Guide forArchitects and Contractors: www.architects.org/emplibrary/CD_Recycling_Guide.pdf
Rubbermaid. Motorized tilt trucks enable easier and safer transportation of loads up to 1,000 pounds without a pallet or forklift, the maker says. The battery-powered unit has a drive speed of 1 to 3 mph over a variety of surfaces and terrain, offering up to five hours or 15 miles of operation on a single charge; the battery recharges in eight hours from a 120-volt outlet. The ergonomic steering handle can only be operated with two hands, making the truck safer to steer and maneuver, and the hinged frame is designed to stay in a tilted position for easier loading and unloading. 800-347-9800.
Green Jobsites. The Grindzilla (C1400) mobile materials shredder and container for wood, drywall, and cardboard waste boasts a 2-ton-per-hour throughput rate and foreign matter recognition to mitigate contamination. The grinder offers a conveyor loading belt and optional side discharge for more flexibility; the 14-cubic-foot container enables easy transport to the recycling facility or other location for shredded material reuse. 678-569-0385.
ProTainer. The Pro-Roll Off trailer system enables self-hauling of various containers to minimize outside dumping fees and control the jobsite waste stream. A gooseneck hitch and versatile bed (including flatbed accessory) complement the powerful hydraulic hook-lift or cable pull with up to 16,000-pound hoist capacity. A remote-control pendant allows operation by a single user. All components are heavy-gauge structural steel for durability and year-round use. 800-248-7761.
Sollenberger Silos. Modular precast bunker panels measure 8 feet 6 inches to create any container shape and capacity needed, and are easily expanded and/or relocated for subsequent phases or jobs. A bolted tongue-and-groove assembly ensures stability; corner and center pieces and optional covers are available to complete and enclose the bin. They also can be used/reused as site barrier and retaining walls. 717-264-9588.
Bayhead Products. Self-dumping hoppers made of molded polyethylene are designed to work with a forklift or manually with optional casters on a welded steel frame. Several models are available with capacity ranging from 5/8 to 3.0 cubic yards and 750 to 1,700 pounds. Molded plastic also is lightweight, quiet, easy to clean, corrosion-resistant, and safer due to no sharp edges. The hoppers are offered in a variety of solid colors with optional hinged lids, drains, and stenciling. 800-229-4323.
Galbreath. This side-loaded, heavy-gauge-steel roll-off recycling container offers up to 33 cubic yards of capacity and the option of multiple hinged doors for convenience. Featuring 12-gauge-steel partitions for effective materials separation, if desired, the container is compatible with most major brand roll-off and hooklift systems. It is available in 12- to 24-foot-long models. 800-285-0666.
Morbark. The model 3800 wood track hog mobile grinder processes mixed woods, including clearing debris and lumber, into usable/saleable chips. A proven drive-line protection system guards against catastrophic damage from contaminants. The grinder features a large in-feed opening, an 8-3/4-cubic-yard in-feed hopper, and two hydraulically driven aggregate-grade belt conveyors that can be folded for transport. The grinder automatically adjusts feed rates and monitors pressures and feed wheel position to maximize production and engine efficiency. 800-831-0042.
This front-loaded spilt recycling container provides two contrasting-color compartments for easy separation of waste and recycled material that mitigate cross-contamination. Four sizes are available, in 50/50 or 60/40 waste-recycling ratios, ranging from 4 to 10 cubic yards of overall capacity. A sliding lid mechanism automatically regulates how materials are disposed or recycled, never allowing the two bins to mix during pickup, the firm claims. 800-565-1723.
Meese Orbitron Dunne. Ship Shape-brand bulk forklift containers are made from 100 percent recycled plastic or blended content from the company's excess and scrap material. For dry materials handling/recycling applications, the weatherproof and corrosion-resistant containers offer payloads up to 50 cubic feet and 700 pounds. Containers can be stacked two high when covered and provide a molded lift design to eliminate pallets; optional casters also are available. 800-772-7659.